White light emitting LEDs generally comprise a blue emitting LED combined with a phosphor layer that is stimulated by the blue emission of the LED into emitting yellow light, the combination of the yellow and blue emissions providing a white light. For normal direction, vertical to the surface of the LED die or vertical to the surface of the phosphor layer with an emission angle of 0°, the path length in the phosphor layer of the light rays emitted by the blue emitting LED is equal to the thickness of the phosphor layer. For increasing emission angles the path length for blue light rays increases. Accordingly the fraction of absorbed blue light rays by the phosphor layer is lower for the light rays with an emission angle of 0° than for the light rays with an increasing emission angle. Since the converted light emitted by the phosphor layer always has a Lambertian over angle distribution, the white light emitted by the LED has a higher correlated colour temperature for normal emission with an emission angle of about 0°. Generally, the phosphor layer is a Y3Al5O12:Ce3+ (YAG:Ce). In case of such a YAG:Ce phosphor layer emitted light becomes yellowish with increasing emission angle, perceived as yellow ring. To solve the yellow ring problem it is known to increase the scattering power of the phosphor layer and/or to add a scattering layer on top of the phosphor layer. For both, the reduction of the yellow ring problem results in a reduction of the LED efficiency, since scattering is accompanied by light reflection leading to light losses. In particular, scattering of the down-converted phosphor emission leads to reflection with accompanied reflection losses.